I purchased a Dwarf Meyers lemon tree a month ago. I came in a 5 gallon bucket and it was very healthy. Three week ago I transplanted it into a larger pot and it has been dropping it's leaves and some of the stalks are bare. The leaves are turing light green to yellow then falling. There are blossoms but they are turning brown. I water it once a week. Last weekend I gave it a dry citrus fertilizer 13-6-6. What am I doing wrong?
Probably overwatering-- with citrus, a fixed watering schedule is a recipie for disaster. By increasing the pot size you added soil that will retain moisture longer since it does not have roots to use the moisture. In general, when repotting, you should not increase pot size more than 2 inches due to the potential to retain water. Also citrus like a very fast draining soil. Citrus should only be watrered when the soil is dry at least 2-3 inches deep. Skeet